DNA loaded carrier preferential extravasation from tumor blood vessel

Non-viral gene delivery carriers were prepared by using DNA/polyethylenimine/polymethacrylic acid (DPP) polyplexes and its extravasation from tumor blood vessel was evaluated with mouse dorsal skin fold window chamber model. The DNA/PEI (DP) complex with a ratio of N to P (10/1) was coated with polymethacrylic acid, and the ratio of PMA to DNA complex in DNA/PEI/PMA (DPP) polyplex was fixed 0.03 (w/w). The surface charges of the DP and DPP polyplex were positive 26 and 15, respectively. The size of DP and DPP polyplex were 161 nm and 195 nm. The transfection efficiencies in HepG2 cells were about 30-fold and 20-fold higher than that in HeLa and L/C cells in the presence of 50% serum, respectively. The DPP polyplex showed a reduced erythrocyte aggregation activity and a decreased cytotoxicity in cancer cells. After being incubated 30 min, Fluorescently labelled DPP polyplex uptaken by cancer cells decreased, compared with DP by measuring flowcytometry. DPP polyplex penetrating through tumor blood vessel appeared fast and stayed longer in tumour interstitial, this fact was observed from mouse dorsal skin fold window chamber model.